Art of recovery of solids from their solutions



Patented Sept. 21 1926.

jwAtrER Ho'wE nIcKERsoN, OF EAST oRANeE'NEw JERSEY.

- STA RT or REcovERY somns FROM THEIR soLuTIoNs.

No Drawing.

The invention relates to a process for the recovery of solids from their solutions thru at'temperatures as high as1000 the atomization or spraying under such conditions as toof the solutions roduce solid particles having a glazed sur ace, whereby the particles are rendered substantially nonhygroscopic.

The present application is a continuation part of my co-pending application for in U. S." Letters Patent, filed November 16th,

Serial No. 262,763, 1918,. and wherein I there is discloseda process for'treating the a waste liquors obtained in the production of paper pulp by the sulfite process, in manner such that a dry obtained therefrom which has a powdered product is glazed surface rendering said powder substantially non-hygroscopic whe reas the products heretofore obtained would coalesce :under unfavorable. atmospher pasty or a hard'solid ic conditions into a mass. These Waste liquors, commonly known as waste sulfite hquors,

are-"complex compounds of a .gen-

erally brownish color which, when concentrated, vform a viscid sy adhesive and binding properties. ,In accordance with the process,

treated for tion to' be rup or liquid having the soluthe recovery of the solids contained therein is, preferably, first heated to approximately the; boiling point of the solution, or supe finely divided as by spraylng or by atomizmg. Y

The finely divided brought tion, the excess rheated; and is then.

solution is then I into contact with a gas at a'tempera-ture above the boiling point ofjthe soluof temperature depending upon the character of the solution and particularly upon the desired characteristics of thefinished product, bu

relatively to the critical temperature of thev material being dried.

t beingj initially high In some instances, gas

F. may beused in connection with solutions of organic materials. Also, the

degree of subdivision of the solution is a factor in'determining the character of the product obtained as to whether it shall be of small, dense. particles or of large and more or particles.

Application filed November 12, 1921. Serial 2N0. 514,819.

It is of vital importance in the process to have the finely divided solution contact with the-gas at the highest temperature of same employed; and, also, that the final gas temperature shall not fall below the boiling point of the solution. There is thus produced, apparently-by theinitially high temperature-to which the finely divided solution is first sub ected, an intense and exceedingly rapid evaporation and the effect of which is -maintained thru the. retentionof the temper term glazed particle used in this application to describe the physical character of the productobtained is intended to denote par ticles the material of which is smooth, shiny and glassy in appearance, is apparently unitary and homogeneous in structure and which in general resembles in physical ap- 7 pearance small drops or fragments of a soild amorphous substance such as glass. This is in contrast to a particle of rough,

.granular, composite character'composed of a large number of independent component parts and clearly having the appearance of being an aggregate rather than a continuous amorphous mass.

I claim:- I

1. The method of converting Waste sulfite liquor into the form of dry glazed particles which comprises introducingthe said liquor in finely divided'condition- Into a current of heated gas at substantially the hottest portion thereof, conducting said material along with said gas through the dryi'lng chamber at a temperature sufliciently high to form the said glazed, particles, and then separating and collecting said particles from the gas.

' 2. The method of converting liquid materials which at some degree of concentration are sticky, viscid and syrupy into the less hollow and light form of dry glazed particles which com current of heated drying gas at substantially the hottest portion thereof, permitting the said hot gas together with the said sprayed material to pass through the drying I chamber and to remain in intermixed condition for a period of time suificiently long to permit formation-of the said glazed particles and then collecting the said glazed particles from the current of spent gas issuing from the drying chamber. 10 Signed at New York in the county of N ew York and State of New York this 10th day of November, A. D. 1921.

WALTER HOWELL DICKERSON. 

